Rio Maniqui, Bolivia

Rio Maniqui in the Beni area of Bolivia is a meandering alluvial sand-bed river which began moving laterally at the rate of about 20 m per year at the point of bridge construction. As a result of this stream migration, the completed span was left stranded in the middle of the river, and the continuing movement of river threatened to literally leave the bridge on dry land. The firm directed field investigations, performed hydrologic and hydraulic modeling, and recommended the placement of permeable deflectors using locally available trees, which successfully arrested the lateral migration of the stream at very low cost and with minimum intervention in the river.